Scroll machines in general and particularly scroll compressors are generally provided with a hermetic shell which defines a chamber within which is disposed a working fluid. A partition within the shell divides the chamber into a discharge pressure zone and a suction pressure zone. A scroll assembly is located within the suction pressure zone for compressing the working fluid. Generally, these scroll assemblies incorporate a pair of intermeshed spiral wraps, one of which is caused to orbit relative to the other so as to define one or more moving chambers which progressively decrease in size as they travel from an outer suction port towards a center discharge port. An electric motor is normally provided which operates to drive the orbiting scroll wrap via a suitable drive shaft.
The partition within the shell must allow compressed fluid exiting the center discharge port of the scroll assembly to enter the discharge pressure zone within the shell while simultaneously maintaining the integrity between the discharge pressure zone and the suction pressure zone. This function of the partition is normally accomplished by a seal which interacts with the partition and with the scroll member defining the center discharge port.
The discharge pressure zone of the hermetic shell can also function as a muffler chamber and is normally provided with a discharge fluid port which communicates with a refrigeration circuit or some other type of fluid circuit. The opposite end of the fluid circuit is connected with the suction pressure zone of the hermetic shell using a suction fluid port extending through the shell into the suction pressure zone. Thus the scroll machine receives the working fluid from the suction pressure zone of the hermetic shell, compresses this working fluid in the one or more moving chambers defined by the scroll assembly and discharges the compressed working fluid into the discharge pressure zone of the compressor. The compressed working fluid is directed through the discharge fluid port to the fluid circuit and returns to the suction pressure zone of the hermetic shell through the suction port.
In certain compressors, the center discharge port is positioned so that relatively hot compressed gas is discharged toward a local area on the interior surface of the hermetic shell in which the compressor is disposed. The compressed discharge gas is normally relatively hot. However, under certain conditions, such as a loss of charge, system blocked fan operation, or transient operation at a high compression ratio, the discharge gas may become exceedingly hot. When this hot compressed gas impinges on the interior of the shell, an undesirable localized hot spot is formed. This localized hot spot can present a hazardous situation as well as reducing the strength and durability of the shell material.
Further, when compressed gas impinges on the interior surface of the shell, noise and vibration are transmitted directly to the shell. When the scroll machine is used as a compressor in refrigeration, air conditioning and heat pump applications, it is particularly advantageous to maintain the lowest operational noise level as possible. Accordingly, the continued development of scroll machines and their fluid systems has been directed to reducing both the operational noise levels of the machines as well as eliminating the problems associated with the discharge of the relatively hot discharge gases.
The present invention provides the art with a discharge duct which directs the relatively hot discharge gases from the center discharge port of the scrolls to the discharge port of the discharge pressure zone of the compressor. The discharge duct significantly reduces any localized hot spots on the compressor shell.
Other advantages and objects of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims and drawings.